1. Field of the Invention
The invention relates to the lowerable roof of a convertible with a front element, a middle element and a rear element which can all be moved out of a closed position which covers the motor vehicle interior by a bearing means into an open position in which they are deposited on top of one another in a rear-side convertible top compartment, the front element being movably supported on the middle element.
2. Description of Related Art
Published German Patent Application DE 196 42 152 A1 discloses a generic lowerable roof of a motor vehicle in which the front element of the roof is movably supported by means of a four-bar mechanism on the middle element and the latter in turn is supported via the four-bar mechanism on the rear element. The rear element is movably supported via two rods on the body. When the roof is being opened first the rear element is swung and in doing so entrains the front element and the middle element in a position which is unchanged to one another. Via the rod which supports the rear element motion is initiated to the two four-bar mechanisms of the front element and the middle element, i.e., the mechanisms which are coupled to one another, so that the front element is swung to under the middle element and the two elements together are swung to under the rear element. The roof elements in this identically cambered arrangement stacked on top of one another are lowered into the convertible top compartment.
The object of the invention is to devise a lowerable roof of the initially mentioned that is provided with an improved support and movement mechanism for the front element.
This object is achieved in accordance with the present invention in that the front element can be lowered or raised by a carrier means which supports the front element on the middle element when the roof is being deposited with respect to the middle part and can be moved to over or under the middle part by a lengthwise guide means. While in the roof known from the prior art the front element is swung by means of the four-bar mechanism over a comparatively large pivot radius to under the middle element, in the roof according to the invention, a small raising or lowering motion is sufficient, with which the front element is raised or lowered relative to the middle element depending on the alternative only to the extent that the front element can be pushed over or under the middle element.
In one preferred embodiment, the carrier means contains a four-bar mechanism which supports the front element on the middle element, which mechanism has a raising and lowering motion controlled by the deposition motion of the roof. Control can take place by a mechanical coupling which, for example, contains a coupling rod which couples the four-bar mechanism to the bearing means which movably supports the middle part on the body. Thus, no additional drive is necessary for swinging of the front element.
Feasibly, the carrier means or the four-bar mechanism contains a carrier element which is movably guided on the lengthwise guide of the front element.
Preferably, the carrier means contains a four-bar mechanism which supports the front element on the middle element and which is movably guided on the lengthwise guide of the middle element and during lengthwise displacement of the front element relative to the middle element executes the raising and lowering motion of the front element by a control means. Raising and lowering the front element are thus initiated by the front element which has been pushed in the lengthwise direction. The front element can be moved especially by a drive means which contains, for example, an electric motor with drive cable connections to the front element.
The swinging motion of the four-bar mechanism is controlled, for example, by a lever which is connected to the four-bar mechanism and has a control element which is guided in a control cam. The control cam can be formed as a unique cam path on the middle element or the lengthwise guide forms at least one section of the control cam.
Preferably the bearing means of the middle element of the roof is formed by two rods which form the main four-bar mechanism, but there can also be other bearing and movement means.
One especially simple configuration which saves space when deposited calls for the rear element to be deposited relative to the front element and the middle element in an oppositely cambered position in the convertible top compartment. To do this, especially the rear element is attached to one of the rods of the main four-bar mechanism which supports the middle element.
Embodiments of the roof are explained in detail below with respect to the accompanying drawings.